Method and device for measuring the activity of nickel ions

ABSTRACT

A DEVICE FOR MEASURING AN ACTIVITY OF NICKEL IONS COMPRISES A SELECTIVE ELECTRODE AND A REFERENCE ELECTRODE IMMERSED IN A SOLUTION CONTAINING NICKEL IONS, SAID SELECTIVE ELECTRODE INCLUDING A DISC IN A BATCH COMPOSITION WHICH COMPRISES A COMBINATION OF NICKEL CHALCOGENIDE AND AT LEAST ONE MEMBER SELECTED FROM THE GROUP CONSISTING OF SILVER TELLURIDE AND SILVER SELENIDE OR A COMBINATION OF   SILVER SULFIDE AND AT LEAST ONE MEMBER SELECTED FROM THE GROUP COONSISTING OF NICKEL TELLURIDE AND NICKEL SELENIDE.

March 12, 1974 KENJI HIGASHIYAMA ETAL 3,796,642

METHOD AND DEVICE FOR MEASURING THE ACTIVITY OF NICKEL IONS Filed Feb. 28, 1972 FIG.1

United States Patent Oflice 3,796,642 Patented Mar. 12, 1974 US. Cl. 204-1 T 12 Claims ABSTRACT OF THE DISCLOSURE A device for measuring an activity of nickel ions comprises a selective electrode and a reference electrode immersed in a solution containing nickel ions, said selective electrode including a disc in a batch composition which comprises a combination of nickel chalcogenide and at least one member selected from the group consisting of silver telluride and silver selenide or a combination of silver sulfide and at least one member selected from the group consisting of nickel telluride and nickel selenide.

BACKGROUND OF THE INVENTION The invention relates to a device for measuring an activity of nickel ions and more particularly to a device comprising a selective electrode responsive to the activity of nickel ions and a reference electrode.

Nickel ion activity can be determined by several methods such as chelatometric titration, spectrophotography and polarography. However, these methods generally require troublesome pretreatment for the sample before the measurement of nickel ions.

It is desirable for chemical industry to have a device for measuring the activity of nickel ions in a solution without any troublesome pretreatment similar to that of a pH glass' electrode for measuring the pH value of a solution without any pretreatment of the solution to be tested. An object of this invention is to provide a device for measuring directly the activity of nickel ions in a solution.

-A further object of this invention is to provide such a measuring device characterized by a high sensitivity to nickel ions.

Another object of this invention is to provide a nickel ion measuring'device characterized by a high response to the nickel ions.

These and other objects of this invention will be apparent upon consideration of the following detailed description, taken together with accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a device for measuring nickel ions in a solution in accordance with the invention; and

FIG. 2 is a cross sectional view of a disc for use in the device of FIG. 1.

A device for measuring an activity of nickel ions according to the present invention comprises a selective electrode and a reference electrode immersed in a solution containing nickel ions, whereby only another surface contacts with said solution. Said nickel ion-selective electrode includes a disc which is in a batch composition comprising a combination of nickel chalcogenide and at least one member selected from the group consisting of silver telluride and silver selenide, or in a batch composition comprising a' combination of silver sulfide and at least one member selected from the group consisting of nickeltellmide and nickel selenide. Said batch composition according to the present invention achieves a nickel ion-selective electrode having a high sensitivity and a wide application range with pH value in a solution to be tested.

Referring to FIG. 1, reference character 10 designates, as a whole, a selective electrode which comprises a disc in a batch composition according to the present invention. Said lead 3 is enveloped by a sealed wire 4. A combination of said disc 1 and said lead 3 partly enveloped by said sealed wire 4 is enclosed in a housing 2 so that another surface of said disc 1 contacts with a solution 6. Said housing 2 is filled with an insulating resinous material 5. A reference electrode 7 partly immersed in said solution 6 is electrically connected to one terminal of a voltmeter 8 having a high impedance. Said lead 3 is electrically connected to another terminal of said voltmeter 8.

A variation in the logarithm of the activity of nickel ions in said solution 6 has substantially linear relation to the variation in the potential between said selective electrode 10 and said reference electrode 7, both being partly immersed in said solution 6. One can use any available and suitable electrode such as a saturated calomel electrode or a silver-silver chloride electrode as said reference electrode 7.

Said disc 1 is in a batch composition comprising a combination of 560 wt. percent of nickel chalcogenide and 40-95 wt. percent of at least one member selected from the group consisting of silver telluride and silver selenide, or in a batch composition comprising a combination of 40-95 wt. percent of silver sulfide and 5-60 wt. percent of at least one member selected from the group consisting of nickel telluride and nickel selenide in accordance with the invention.

A batch composition comprising a combination of more than 60 wt. percent of nickel chalcogenide and less than 40 wt. percent of silver chalcogenide results in a low sensitivity of resultant electrode.

A batch composition comprising a combination of less than 5 wt. percent of nickel chalcogenide and more than 95 wt. percent of silver chalcogenide results in a low sensitivity and a long response time of resultant electrode.

Nickel chalcogenide referred to herein is defined as nickel sulfide, nickel selenide and nickel telluride.

A batch composition referred to herein is defined as a composition of starting materials before heating.

A better result is obtained by using a batch composition wherein said silver sulfide includes at least one member selected from the group consisting of silver selenide and silver telluride, the weight ratio of said silver sulfide to said one member being in a range from 1 to 10. This batch composition results in a high sensitivity and a short response time of resultant electrode.

A more preferable batch composition comprises a combination consisting essentially of 10 to 30 wt. percent of nickel telluride and 70 to Wt. percent of silver sulfide.

A longer operation life can be obtained by providing said disc with a noble metal electrode such as gold, paradium or platinum electrode. Referring to FIG. 2, disc 1 has a noble metal electrode 9 applied to one surface thereor by applying an available commercially noble metal electrode 9 by any available and suitable method such as soldering. Said noble metal electrode 9 can be prepared by, for example, vacuum-depositing of a noble metal film or by applying a available commercially noble metal paint.

The disc for use in said selective electrode can be obtained by heating a pressed body of a mixture of a given batch composition in accordance with a conventional ceramic method.

A mixture of starting meterials of a fine powder form in a given batch composition according to the present invention is mixed well in a dry method by any suitable and available equipment and is pressed into a disc in a desired form at a pressure of 100 to 20,000 kg./cm. The pressed disc is heated at a temperature of 100 to 600 C. for time period of l to 10 hours preferably in a non-oxidizing atmosphere, such as nitrogen or argon.

The device according to the invention can be reliably used at temperatures from to 95 C. The measured potential versus the logarithm of the activity of nickel ions is substantially linear relation.

Many kinds of diverse ions such as sodium, potassium, calcium, magnesium, cadmium, cobalt, aluminum, zinc, chloride, sulfate and perchlorate ions are tolerated and may coexist during the measurement of the activity of the nickel ions. However, cupric, lead, chromium(III), ferric, silver, mercuric, iodide and sulfide ions should be removed from the solution to be measured.

EXAMPLE 1 A mixture of 25 wt. percent of nickel telluride and 75 wt. percent of silver sulfide is mixed well in a dry method and is pressed at a pressure of 10,'000-20,000 kg./cm. into a disc 15 mm. diameter and having a 3 mm. thickness. The pressed disc is heated at 400 C. for 2 hours in purified nitrogen gas stream having a flow rate of 0.2 l./min. The sintered disc is polished, at both surfaces, with silicon carbide abrasive and then with diamond paste into a thickness of 2 mm. The polished disc is provided, at one surface, with a gold electrode which is obtained from Du Pont gold paint #8115. The polished disc is connected, at the gold electrode, to a lead partly enveloped by a sealed wire and is mounted in a housing of polyvinyl chloride resin. The housing is filled with epoxy resin so as to build a selective electrode as shown in FIG. 1. A combination of the selective electrode and a saturated calomel electrode as a reference electrode is immersed in an aqueous solution of pure nickel nitrate at 25 C. The potential between the selective electrode and the calomel electrode is measured by a voltmeter for use in a pH meter.

The device measures the activity of nickel ions with a high sensitivity as shown in Table 1.

A device for measuring the activity of nickel ions is prepared in a manner similar to that of Example 1. A disc of Example 2 includes nickel sulfide and silver tel luride. The preparation of the disc is similar to that of Example 1. The potential between the selective electrode and the calomel electrode in an aqueous solution of pure nickel nitrate is measured with the same procedure described in Example 1. The device measures the activity of nickel ions with a high sensitivity as shown in Table 2.

.TABLE 2 Potential, mv.

1 Weight ratio of nickel sulfide: silver telluride.

EXAMPLE 3 The device for measuring the activity of nickel ions is prepared in a manner similar to that of Example 1. A disc of Example 3 consists of nickel selenide and silver sulfide. The preparation of the disc is similar to that of Example 1. The potential between the selective electrode and a saturated calomel electrode in an aqueous solution of pure nickel nitrate is measured by the same procedure described in Example 1.

TABLE 3 I Potential, mv.

Activity of nickel ions, M:

1 Weight ratio at nickel selenide: silver sulfide.

EXAMPLE 4 The device for measuring the activity of nickel ions is prepared in a manner similar to that of Example 1. A disc of Example 4 includes nickel telluride and silver selenide as the starting materials. The preparation of the disc is similar to that of Example 1. The potential between the selective electrode and a saturated calomel electrode in an aqueous solution of pure nickel nitrate is measured by the same procedure described in Example 1.

TABLE 4 Potential, mv.

1 Weight ratio of nickel telluride: silver selenide.

EXAMPLE 5 TABLE 5 Potential, mv.

Activity of nickel ions, M:

1 Weight ratio 01 nickel selenide: silver selenide.

EXAMPLE 6 A device for measuring the activity of nickel ions is prepared in a manner similar to that of Example 1. A disc of Example 6 includes 25 wt. percent of nickel telluride, 35 wt. percent of silver sulfide. The preparation of the disc is similar to that of Example 1. The potential between the selective electrode and a saturated calomel electrode in an aqueous solution of pure nickel nitrate is measured with the same procedure described in Example 1. The device measures the activity of nickel ions with a high sensitivity as shown in Table 6.

A device for measuring the activity of nickel ions is prepared in a manner similar to that of Example 1. A disc of Example 7 includes 5 wt. percent of nickel sulfide, 25% of nickel telluride, 20% of silver sulfide and 50% of silver selenide as the starting materials. The preparation of the disc is similar to that of Example 1. The potential between the selective electrode and a saturated calomel electrode in an aqueous solution of nickel nitrate is measured with the same procedure described in Example 1. The device measures the activity of nickel ions with a high sensitivity as shown in Table 7.

A device for measuring the activity of nickel ions is prepared in a manner similar to that of Example 1. A disc of Example 8 includes 10 wt. percent of nickel selenide, 15% of nickel telluride and 75% of silver sulfide as the starting materials. The preparation of the disc is similar to that of Example 1. The potential between the selective electrode and a saturated calomel electrode in an aqueous solution of nickel nitrate is measured with the same procedure described in Example 1.

TABLE 8 Activity of nickel ions, M: Potential, mv. l" 12 10- 11 10* -35 10- r -63 10- --92 .10 120 What is claimed is:

1. A method for measuring the activity of nickel ions in a solution comprising immersing a selective electrode and a reference electrode in a solution consisting essentially of nickel ions, said selective electrode comprising a disc made from a batch composition which comprises a combination of nickel chalcogenide and at least one member selected from the group consisting of silver telluride and silver selenide and measuring the potential difference between the electrode.

2. A method as defined in claim 1, wherein said batch composition comprises a combination of 5-60 wt. percent of nickel chalcogenide and 40-95 wt. percent of at least 6 one member selected from the group consisting of silver telluride and silver selenide.

3. A method for measuring the activity of nickel ions in a solution comprising immersing a selective electrode and a reference electrode in a solution consisting essentially of nickel ions, said selective electrode comprising a disc made from a batch composition which comprises a combination of silver chalcogenide and at least one member selected from the group consisting of nickel telluride and nickel selenide and measuring the potential difference between the electrode.

4. A method as defined in claim 3, wherein said batch composition comprises a combination of 40-95 wt. percent of silver sulfide and 5-60 wt. percent of at least one member selected from the group consisting of nickel telluride and nickel selenide.

5. A method as defined in claim 3, wherein said silver chalcogenide includes silver sulfide and at least one member selected from the group consisting of silver telluride and silver selenide, the weight ratio of said silver sulfide to said one member being in a range from 1 to 10.

6. A method as claimed in claim 3, wherein said batch composition comprises -90 wt. percent of silver sulfide and 10-30 wt. percent of nickel telluride.

7. A device for measuring the activity of nickel ions in a solution comprising a selective electrode and a reference electrode, said selective electrode comprising a disc made from a batch composition which comprises a combination of nickel chalcogenide and at least one member selected from the group consisting of silver telluride and silver selenide.

8. A device as defined in claim 7, wherein said batch composition comprises a combination of 5-60 wt. percent of nickel chalcogenide and 40-95 wt. percent of at least one member selected from the group consisting of silver telluride and silver selenide.

9. A device for measuring the activity of nickel ions in a solution comprising a selective electrode and a reference electrode, said selective electrode comprising a disc made from a batch composition which comprises a combination of silver chalcogenide and at least one member selected from the group consisting of nickel telluride and nickel selenide.

10. A device as defined in claim 9, wherein said batch composition comprises a combination of 40-95 wt. percent of silver sulfide and 5-60 wt. percent of at least one member selected from the group consisting of nickel telluride and nickel selenide.

11. A device as defined in claim 9, wherein said silver chalcogenide includes silver sulfide and at least one member selected from the group consisting of silver telluride and silver selenide, the weight ratio of said silver sulfide to said one member being in a range from 1 to 10.

12. A device as claimed in claim 9, wherein said batch composition comprises 70-90 wt. percent of silver sulfide and 10-30 wt. percent of nickel telluride.

References Cited UNITED STATES PATENTS 3,591,464 7/1971 Frant et a1. 204l T 3,669,862 6/1972 Hirata et a1 204-495 M 3,672,962 6/ 1972 Frant et al. 204-4 T GERALD L. KAPLAN, Primary Examiner US. Cl. X.R. 204l M 

